She said there had been reports of pupils cursing after hearing parents swear in the playground and in the roads leading to the school.

"You do hear the parents talking to each other and there are some parents who swear,” she said. “It can be carried through to children.

"They do not realise that it is the wrong language and children can pick up on it.

"Some children have heard parents swearing and there have been incidents of children subsequently swearing.

"It is unacceptable but we can't blame children, they are just repeating what they have heard.

"But we have explained to them why it is not acceptable and why it will not be allowed."

Governors at the school supported the move by Mrs Wakelin to try and curb the use of bad language and suggested most parents would feel the same way.

One governor, who did not want to be named, said: “There will always be parents who use bad language because they use it at home and that’s just what happens, and you get children who use words like that because that’s what their parents are doing.

“But when you’re in front of other people’s children you should watch what you’re saying.

“Parents do get upset when their children have heard words they don’t want them to hear.

“It’s about consideration for others. It’s thinking of the other children in the school, and some parents don’t like to hear these words either.”

One of the school’s rules was to show respect to other people and not swearing was part of this, she added.

Past research has found that 90% of parents swear in front of their children, with the average child hearing their mother or father utter six expletives a week.

Only a third of parents punish their children for swearing, a separate study found.

Men have been found to be more likely than women to use bad language in front of their children.

Teachers have warned previously that pupils as young as four and five are using bad language in the classroom because of the swearing and vulgarity to which they are exposed on television.

The use of rude hand gestures in the playground was also said to be on the rise as a result.

Last year Jon Reynard, the head teacher of Seaford Primary School in Seaford, East Sussex, wrote to parents to complain about “unacceptable” behaviour and language.

He said there had been “inappropriate behaviour and very inappropriate language” at the school gate” and told them: “I would respectfully request that all adults act as role models for the children of our school at all times.”